Re: [RFC]: userspace memory reaping

On Wed, Nov 04, 2020 at 07:58:44AM +0100, Michal Hocko wrote:

On Tue 03-11-20 13:32:28, Minchan Kim wrote:

quoted

On Tue, Nov 03, 2020 at 10:35:50AM +0100, Michal Hocko wrote:

quoted

On Mon 02-11-20 12:29:24, Suren Baghdasaryan wrote:
[...]

quoted

To follow up on this. Should I post an RFC implementing SIGKILL_SYNC
which in addition to sending a kill signal would also reap the
victim's mm in the context of the caller? Maybe having some code will
get the discussion moving forward?

Yeah, having a code, even preliminary, might help here. This definitely
needs a good to go from process management people as that proper is land
full of surprises...

Just to remind a idea I suggested to reuse existing concept

    fd = pidfd_open(victim process)
    fdatasync(fd);
    close(fd);

I must have missed this proposal. Anyway, are you suggesting fdatasync
to act as a destructive operation?

write(fd) && fdatasync(fd) are already destructive operation if the file
is shared.

You don't need to reaping as destruptive operation. Rather than, just
commit on the asynchrnous status "write file into page cache and commit
with fsync" and "killing process and commit with fsync".